This can be mostly easily demonstrated by a screenshot:
On the left side an example webpage was opened in Safari, on the right side the same page as a weblocation opened in DTP’s builtin browser. Both pages were scrolled to top. But as you can see in DT’s browser the first line of the page was hidden by address bar.
The tricky part is that I didn’t figure out how to reliably reproduce the issue. Sometimes it happens, other times not. When it happens, refreshing page won’t make a difference. I initially presumed this is caused by the height of extra tab bar when there’re multiple tabs in a window. But after restarting DTP, the bug disappeared. (Will keep an eye on it, trying to find way to reproduce.)
This would be great, thanks a lot.
For the record…
So this also happens in preview window. And behavior is still intermittent. Notice the scroll bar on the right side is cut off by address bar.
Does this depend on the type of the viewed document? Or what you viewed before opening this document?
Based on my testing, it probably happens to all webpage-like doc types, including weblocation, webarchive, and html docs, but not affecting pdf, txt, etc.
Well, it just happens on and off. It’s really confusing… I’ve recorded several videos to demonstrate:
The first video (as a gif) shows I repeatedly open the same webloc in document window. 1st time the bug not triggered, 2nd time the bug triggered, 3rd time not triggered, 4th time triggered.
The second video (as a gif) shows the same but in preview window.
The third video (as a gif) shows I successively open each weblocation doc in the inbox in preview window. Some of them are rendered normally, others not. This video is somewhat messy, not as clear as last two.
Do you use RSS feeds in your database too?
No, I’m not familiar with the feature yet 
I’ve manually saved several urls from StackExchange for personal use. And to record the videos posted previously, I just duplicated 5 of them to an empty test database. It looks to me the problem can randomly manifest itself to any web-based document, no matter how I saved them. 
